Wilhelm klinkerfues



(No Model.)

- W. KLINKBRFUES.

HYiaosooPE.

220. Patented Apr. 3, 1883;

N. PETERS. Fbflb-lmwgraphfir, Washington. p.c.

UNITED STATES PATENT FFICE.

WILHELM KLINKERFUES, OF GOTTINGEN, GERMANY.

HYGROSCOPE.

SPECIFICATION forming part of Letters Patent No. 275,220, dated April 3, 1883.

- Application filed January 16, 1883. (No model.)

To all whom it may concern Be it known that I, WILHELM KLINKER- FUES, a subject of the Emperor of Germany, and residing in the cityof Gottingen, Germany, have invented certain new and useful Improvements in Meteorological Indicating- Instruments, of which the following is a specification.

This invention relates to hair hygrometers, and is also applicable to other instruments in which the hygroscopic qualities of the human hair are employed for indicating the relative moisture of the atmospheric air, in combination with air-pressure and temperature of air. As a hair or a hair string ofquality and preparation as used for hygrometers or weatherinstruments generally changes its length not in geometrical proportion to the changes of relative moisture of the air, and as, for instance, a hair string of one hundred units of length is, by an increase of relative moisture from 0 per cent. to ten per cent., lengthened 0.517 units, while by an increase of relative moisture from ninety per cent. to one hundred per cent. the length is increased only 0.117 units, a practical difliculty arises in construction and adjustment of such hygrometers and other meteorological instruments connected therewith, for the reason that they cannot have their corresponding scales divided into equal parts or divisions without the use of more or less complicated mechanical arrangements of adjustment. By the present inven-' tion this difficulty can be overcome with an exactness that fully suffices for most practical purposes.

Figure 1 is a front view of an apparatus illustrating my invention. Fig. 2 is an axial section of the same, and Fig. 3 is a diagram illustrative of the action of the non-hygroscopic string on the hygroscopic hair string.

Suppose a hair or hair string, h, be withits one end secured at a fixed point, (I, and to its other end secured to an arm, I), fastened to the axle e, which is influenced by a spring, m, in such a manner that the hair string h is continually kept extended in astraight line. This arm b will, by an increase of relative moisture of the air and corresponding lengthening of the hair string h, be caused to turn to the left, together with the axle e. If to this arm b a non-hygroscopic string, 1, be attached with its one end, while its other end is fastened to a fixed part or standard, (I, of the instrument, and it this string 1 is of such length that it will remain bent during all changes in length of the hair string 71, this bend (designated by w in the drawings) will be of different widths, according to the changes in length of thehair string It. With an increase otthe length of the hair string h-that is, during an increase of percentage of relative moisture-this bend or will be reduced, whileit will be increased with a decrease of relative moisture of the air. By connecting the bend or of the string 1 by means of an eye, 0, and another non hygroscopic string, 71, to a roller or lever on the index-axle 2, which latter, by another string, 1;, and roller r and a small spring, 19, keeps the stringl taut, the indicating-hand of the shaft zwill, according to the changes of-relative moisture, either turn to the right or left, and indicate either a rise or fall of percentage of relative moisture of the air.

As the size of the bend or of string 1 during equal changes in length of stringhordistance between the points at which 1 is fastened does not grow or decrease in geometrical propor-' tion with the hair string h or the aforesaid distance, but as, on the contrary, a: increases in decreasing proportion with equal reductions in length of the hair-string h, as will be understood with reference to Fig. 3 of the drawings,while it grows in increasing proportion with equal increases in length of h, this geometrical attribute of the bend at, in combination with the aforesaid attribute of a hair string, according to which the dimensions in length increase in decreasing geometrical proportions with the percentage of relative moisture of the air, allows the use or application of a scale with equal divisions for all percentages of relative moisture.

If the bracket d, to which the hair string h and string 1 are attached, instead of being a fixture to the ground-plate of the instrument,

is connected to the free end of a thermometrical ring, after Bourdons system, or to the free end of an aneroid-rin g, after Bourdons system, or to the diaphragm of an aneroid-box, after Vidis system, this bracket d will, according to the changes of temperature or to the barometric alterations of air-pressure, come nearer to or be moved farther apart from the axle e, and will consequentlyinfluence the movements of axle z and the indicating-hand,in combination with the hygroscopic alterations of hair string h. In such combination the invention can usefully be applied to instruments indicating the dew-point of the air or to instruments for foretelling the coming Weather.

What I claim as my invention, and desire to secure by Letters Patent, is-

The combination of a straight hygroscopic hair string, h, and a non-hygroscopic bent string, Z, connected by means of a string, 6,

to the axle z of the index, in such a manner that the shortening of the hair string h deep- 15 ens the bend of the string 1, while the lengthening of the hair string h flattens this bend, all substantially as described, and for the purpose set forth.

YVILHELM KLINKERF UE S.

W'itnesses:

F. ENGEL, FoLs. KRAGKE. 

